1. Field of the Invention
This invention relates to novel semi-synthetic glycopeptides having antibacterial activity, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment.
2. Description of Related Art
The emergence of drug resistant bacterial strains has highlighted the need for synthesizing and identifying antibiotics with improved activity. Naturally occurring glycopeptide antibiotics used to combat bacterial infections include vancomycin and desmethyl-vancomycin compounds having the following structure:
wherein R4 is CH3 for vancomycin, and H for desmethyl-vancomycin.
These compounds are used to treat and prevent bacterial infection, but as with other antibacterial agents, bacterial strains having resistance or insufficient susceptibility to these compounds have been identified, and these compounds have been found to have limited effect against certain bacterial caused by glycopeptide resistant enterococci. Therefore, there is a continuing need to identify new derivative compounds which possess improved antibacterial activity, which have less potential for developing resistance, which possess improved effectiveness against bacterial infections that resist treatment with currently available antibiotics, or which possess unexpected selectivity against target microorganisms.